theorem minle1 (a b: nat): $ min a b <= a $;
Step | Hyp | Ref | Expression |
1 |
|
eqle |
min a b = a -> min a b <= a |
2 |
|
ifpos |
a < b -> if (a < b) a b = a |
3 |
2 |
conv min |
a < b -> min a b = a |
4 |
1, 3 |
syl |
a < b -> min a b <= a |
5 |
|
ifneg |
~a < b -> if (a < b) a b = b |
6 |
5 |
conv min |
~a < b -> min a b = b |
7 |
6 |
leeq1d |
~a < b -> (min a b <= a <-> b <= a) |
8 |
|
bi2 |
(b <= a <-> ~a < b) -> ~a < b -> b <= a |
9 |
|
lenlt |
b <= a <-> ~a < b |
10 |
8, 9 |
ax_mp |
~a < b -> b <= a |
11 |
7, 10 |
mpbird |
~a < b -> min a b <= a |
12 |
4, 11 |
cases |
min a b <= a |
Axiom use
axs_prop_calc
(ax_1,
ax_2,
ax_3,
ax_mp,
itru),
axs_pred_calc
(ax_gen,
ax_4,
ax_5,
ax_6,
ax_7,
ax_10,
ax_11,
ax_12),
axs_set
(elab,
ax_8),
axs_the
(theid),
axs_peano
(peano1,
peano2,
peano5,
addeq,
add0,
addS)